Shoe sole



Feb. 16, 1932. N. WALLACE l1,845,008

SHOE' SOLE Filed Deo. 24, 1950 Patentes Feb. 16, 1932 UNITED STATI-:s

PATENT OFFICE NOR-MAN "WALLACE, OF CUMBERLAND, MARYLAND, ASSIGNOR TO KELLY-SPRINGFIELD TIRE COMPANY, OF CUMBERLAND, MARYLAND, A. CORPORATION OF NEW JERSEY SHOE SOLE Application filed December 24, 1930. Seriat No. r504,463.

This invention pertains to improvements in the so-called' composite type ofsole as applied to boots yand shoes, and while the preferred illustration discloses a partial or half sole attached as a facing on the conventional sole, it will be understood that the term sole is intended to embrace the accepted interpretation of such term inthe art,

except as to specific limitations herein set forth.

There are, basically, two types of composite solesthat which is either sewed or nailed as a principal means of security to the welt and/or to a sole intended to be supplemented, and that type which relies upon adhesion by cementing and/or vulcanizing to a sole which is to be supplemented.r This invention pertains specifically to the adhesion type, with or without the additional security of marginal attachment by sewing or nailing, and is peculiarly well adapted to serve'as a supplemental facing on a new shoe sole or to serve as a repair facing for one partially An appraisal of the objects attained by" sustain quite expected mileages of upwardy of 20,000 miles; but it is likewise recognized that such tread stock possesses characteris tics of relative stiffness, tendency to heat, separate and to crack which would render it uselessunlessinthe design'of it associated elements of the casing due consideration be taken of the necessity for so relating the other component parts as to physical characteristicsk and proportion that the performance of the wholemay be coordinated to best advantage.

The analogy of the well-known structure of the automobile tire as to its necessary characteristics in service and the shoe sole of this invention is availed of in realizing the novelty of the means devised to attain the resulting efficiency. a 'i The load on the human foot is transmitted through the extremely flexible and yielding kball portion to the zone of the shoe sole, that must be designed to receive it in such manner that the concentrated `stresses shall be absorbed, transmitted and dissipated into the structure to the best advantage.

In short, it has become the chief object of this inventionto produce a composite sole composed of laminated plies of unified material having different and modifying characteristics to most effectively meet the conditions of service; and'specifically to provide an article that will be durable, flexible, thin and of light weight, cool wearing, comfortable to the wearer, waterproof, inexpensive, sightly and readily and efficiently applied by the unskilled.

These and other objects, and specific structural features, will be more fully developed throughout the following discussion, and the appended drawings. illustrate a preferred form and embodiment of the invention.

Figure 1 is a` top plan view of an untrimmed sole in process of being fitted to a shoe. c Y l l Figure 2 is atop plan view, enlarged, of the sole, trimmed, and with portions of the component layersbroken away to illustrate structural features. A

Figure 3 is a sectional view on the line 3-3 of Figure Q, showingthe relationship of the sole with the shoe structure, as applied and trimmed.

The illustrated embodiment comprises a thin and tough wear resistingy rubber compound 17 in which is intimately embedded a sheet 16 of relatively high twist, close-mesh square woven cotton fabric of a preferred con.

struction of about seventeen vsquares pery inch. Thissole fabric 16 may be advantageously rubberr coated, or frictioned and coated in the Vwell-known manner. The compound used on 16 is such that the maximum ad-V hesion is `induced Awith the relatively stiff tread stock 17, whereby 'the two supplement each other and workA as a unit'with fabric lill.:

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16 transmitting stresses to underlying laminations and serving as an etlicient unifying means thereto.

The layer 15 of cushion rubber, of appropriate thickness, is applied on rubberized fabric 16 and serves not only as an eicient cushion member to transmit and distribute stresses from the tread, but unities these layers with the super-posed open mesh cushion breaker 14. The cushion breaker 14, as also the top breaker 13, are preferably of open` mesh square Woven cotton fabric of a preferred construction of about twelve squares per inch. These breakers further cushion, dissipate and transmit stresses from adjacent plies. They are heavily rubber coated in the usual Aranner with appropriate compounds; which penetrate the intcrstices to form flex` ible rivets when the Whole is finally vulcanized.

The breaker 15 is marginally stepped back from the trim line ofthe sole, and the breaker' 14 is likewise marginally step )ed back in relation to 15, for the purpose presently eX- plained.

The top gum ply 12 overlays breaker 13 and is coextensive with the marginal dimension of the sole in order that a full attaching surface may be presented to the portion of the shoe with which it to become associated. It is preferred that the Well-known cold cementing process be followed in attaching the sole to the shoe portion, but due to the embedded thread fabric 16 in the tread ply it is quite feasible to sew or nail the sole to the shoe with or Without supplemental cementing.

This top gum 12 is so compounded as to form an intimate union with the portions of all of the underlying plies With Which it contacts.

An efficient manufacturing process consists in; mechanically coating a web of fabric 16 with soft rubber on bot-h sides and then applying additional coats of the tough tread stock 17 to the desired thickness, and thereafter die cutting` the soprepared laver to a molded line 18 (see Figure 1) the soft unvulcanized cushion gum 15 of desired thickness and ofthe same marginal dimension as 16-17 is then applied; thereafter the heavily coated breakers 1'1 and 13, die cut to diminished marginal sizes, are successively applied in the order named upon the surface of 15. At this stage the so-assembled units may be given a suitable vulcanizingl treatment in a platen press, and thereafter the appropriately compounded unvulcanized top gum 1Q is applied and firmly rolled into contact by the process well known in the art. The migration of the vulcanizing elements of the underlying plies may be utilized as a further means for uniting the contacting surface of 12 thereto by subjecting the completely assembled sole to a primary' or secondary mild vulcanization with the exposed top surface of raw gum 12 protected by a backing of glazed muslin or Holland (see Mooiny 1,068,691 of July 29, 1913) the resulting completed sole then consisting of a vulcanized tread and backing plies with the top shoe-attaching surface in a tacky, unvulcanized condition adapted to be united to a foreign surface under the usual cold cementing treatment.

The factory-made sole is preferably oversized to a molded line 18 in order that a marginal excess will afford ample trim-oil" to a line 19 when templated to the particular shoe sole to which it will be applied. It is preferable that the trim line 19 be slightly set back as at A from the margin of the shoe sole and that in the cutting operation a receding bevel B be worked (see Figure 3). This treatment has been found desirable to insure a snug fit and close adhesion of the sole 11 to the shoe bottom 10, without exposed edges to induce scul'ling and marginal se aration.

he progressive stepping back of breakers 13 and 14 With respect to the margin 19 and to each other serves the purposes of building up cushion depth and adhesive stress dissipatin characteristics at the point of maxin'uuu effort under the ball of the foot, and especially provides for a marginally directed taper of the sole, as shown at Figure This 1narginal taper beyond the breakers results in edges substantially thinner than the central portion, whereby the hazard of sculling up the critical marginal attachment is reduced, and the thin edges greatly enhance the appearance of the assembled structure.

In Figure 3 the taper is exaggerated for illustrative purposes. In the preferred form it is found by actual measurement that the thickness of the margin, comprising plies 17, 16, 15 and 12 constitutes only approximately one-half of the central thickness, including the breakers 13 and 14. A preferred form of this sole discloses approximate thicknesses of one-eighth of an inch (1/3) and one-sixteenth of an inch (1) at the center and edges, respectively.

The inclusion of these breakers, either as a single ply or multiply plies as preferred, affords the essential depth of cushion; flexible unification between tread and attaching ply to dissipate and transmit stresses, and provides for absorption and dissipation of heat as an elfective characteristic to add to the comfort of the wearer and contribute to the durability of the sole.

The marginal set back of the breaker element is such, in the different manufactured stock sizes of this article` as to preserve the marginal taper when the final trim is made to accommodate the shoe structure With which it is intended to become associated; it being understood that these soles are regularly supplied to the trade in various stock sizes,

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each of which has marginal excesses adapted to accommodate trimming to several sizes and widths of standard shoe lasts.`

Extensive tests of these thin and ultra flexible soles have demonstrated wearing qualities equal to the performance of leather soles which they have substituted, without separation, and aording full comfortY to the wearer.

It is apparent that various structural modiiications and diierent and well-known manufacturing procedures may be resorted to as alternatives of the preferred description herein given without departing from the spirit of my invention as defined in the appended claims.

TWh at l claim is l. A relatively thin and flexible composite sole, comprising a ply of tough tread stock unified with a rubberized fabric backing; a cushion rubber ply thereon; ay rubberized breaker on said cushion marginally short of the edges of said sole; and a cover ply of rubber on said breaker and coextensive with the margin of said sole, said cover having an unvulcanized exposed surface.

2. A relatively thin and flexible composite sole, comprising a ply of tough tread stock unified with a rubberized fabric backing; a cushion rubber ply thereon and substantially co-extensive therewith; a rubberized breaker on said cushion marginally short of the edges of said sole; and a cover ply of rubber on said r breaker and coextensive with the margin of 3 said sole, said cover having an unvulcanized exposed surface, said cover being intimately united with the portion of said cushion ply which extends marginally beyond said breaker whereby the assembled sole presents thinedged tapering margins and a relatively thick central area.

3. A relatively thin and flexiblecomposite sole, comprising plied tread, tread fabric and cushion rubber marginally coextensive; a

' plurality of breaker plies superposed on said cushion and progressively stepped back marginally from the edges of the tread; and a cover ply of rubber on said breaker plies having an unvulcanized exposed surface, said cover ply intimately united with the portion of said cushion which extends marginally beyond the breaker plies whereby the assembled sole presents thin-edged tapering margins and a relatively thick and more resilient central area.

Ll. A composite sole, comprising a relatively thin and tough tread ply; a relatively thick central area comprising rubberized resilient breaker elements; marginal areas rela- A:l tively thin by omission of said breakers; and

a cover ply of rubber having an unvulcanized exposed surface. n

5. A composite sole, comprising av thin, tough, fabric-backed tread ply; a relatively thick central area comprising resilient cushtough, fabric-backed'tread ply;

relatively` thin by omission of said breaker;

and a `cover ply of rubber substantially coextensive with the marginal dimension of said tread ply.

Gf A composite sole, comprising a thin, a relatively thick central area comprising rubberized resilient breaker elements; marginal areasr relativelythin by omission of said breaker, said areas tapering in depth from the thin to the f thicker area; and a cover ply of rubber having an exposed surface adapted to beattached by cementing to a shoe bottom.

. 7. A composite sole, comprising a thin, tough, tread ply; a top ply of rubber having an unvulcanized` exposed surface; resilient cushion and breaker inserts between the tread and top ply, said inserts tapering from a greater-depthat the central area to a dimin- 5 is'hing depth marginally.y

8. Al composite sole, comprising a thin, tough fabric-backed treadply; a top ply of rubber having an unvulcanized exposed sur- A face; substantially thick cushion and breaker my inserts between the tread and top ply, said i inserts forming a relatively thick pad over a substantial central area of said sole and marginally diminshed in thickness whereby a sole with thin edges and relatively thicker center is formed.

9. A composite sole in blank adapted to be trimmed to a template, comprising a thin, tough, fabric-bound tread ply; a top ply of rubber having an unvulcanized exposed surface; textile rubberized breaker elements completely enveloped between said tread and top ply, said breaker elements forming a pad over a substantial central area of said sole; relatively thin marginal areas formed by contact of said tread and top ply whereby a trimming margin is provided without exposing the margins of said breaker elements.

l0. A composite sole in blank adapted to be trimmed to a template, comprising a tread no ply; a top cover ply of rubber having an exposed surface adapted to be attached to a shoe bottom by cement; said tread and top cover marginally unified to constitute a trimming excess; an enveloped central pad relatively thicker than the said margin, comprising a rubberized textile breaker insert having greater central than marginal depth.

11. A composite sole in blank, comprising a tough, thin, fabric-backed tread ply; a top 12 cover ply of rubber having an exposed surface adapted to be attached to a shoe bottom by cement; an enveloped central pad of cushion gum and textile rubberized breaker fabric marginally stepped lback from the edge of said tread ply and tapering centrally in thickness therefrom.

12. A composite sole in blank of vulcanizable elements, comprising a thin tread ply; a

top cover ply having an unvulcanized exposed surface; a cushion and rubberized breaker fabric constituting a cushion marginally tared in thickness and completely enveloped y said tread and top plies. 5 13. A composite sole in blank of vulcanizable elements adapted to be trimmed to a template, comprising a thin, fabric-backed tread ply and a top cover ply having an exsed surface adapted to unite with a shoe ttom, said tread and top ply united to form a fiat marginal excess; a resilient pad comprising a rubberized textile breaker marginally short of the edge of the said 'lat marginal excess and taperin centrally in thickness therefrom, said breaer completely enveloped by said tread and top plies.

14. A composite sole in blank, comprising a vulcanizable rubber tread and top cover ply marginally unified to form a flat perimetral trim excess; a resilient breaker element of vulcanizable rubberized textile fabric enveloped by said tread and top plies and tapering from edges short of the said flat marginal portions toward the central area of said :2.5 breaker; said sole having edge portions substantially thinner than its central area.

In testimony whereof I affix my signature.

NORMAN WALLACE. 

